1. Field of the Invention
The present invention relates to a method of automatically grinding, with the use of an automatic dresser, a welding electrode of each of a plurality of spot welding machines arrayed along a welding line. The present invention also relates to an apparatus for effecting this method.
2. Description of the Prior Art
Japanese Utility Model Laid-Open Application No. 62-10975 discloses an automatic electrode shaping or grinding machine provided with a holding mechanism for securely holding an electrode chip of a spot welding machine. This automatic electrode grinding machine is installed beside the spot welding machine. When the spot welding machine is out of operation, the electrode chip held by the chip holding mechanism is transported to a position confronting a grinding tool to be ground thereby. According to this disclosure, a plurality of spot welding machines are installed together with respective automatic electrode grinding machines. When a large number of spot welding machines are arranged along a welding line, as many automatic electrode grinding machines are needed, thus resulting disadvantageously in an increased cost of equipment and maintenance. If the welding line does not have enough space to install so many automatic electrode grinding machines corresponding to respective spot welding machines, a worker is obliged to use a grinding tool to grind the electrode of each spot welding machine in a condition in which the welding line is out of operation. Such a welding line requires complicated operations and interrupting the operation of the welding line lowers its productivity.